Pressure-volume-temperature measurements are used in predicting complicated thermo-physical behavior of a fluid, such as, but not limited to, the thermo-physical behavior of reservoir fluids. For example, pressure-volume-temperature measurements are used in developing thermodynamic models describing the state of a fluid at different temperature and pressure conditions.
Conventional pressure-volume-temperature measurements are typically performed in a pressurized cell with a window for visual observation of a sample being characterized. In such systems, the pressure on the sample is maintained by controlling a piston inside the cell. The cell is typically disposed inside an oven to accurately control the temperature of the sample. Volumes of liquid and gas phases inside the cell are monitored as a function of pressure and temperature to study the phase behavior of the sample. Conventional pressure-volume-temperature measurements, however, may take up to several weeks to complete due to the lengths of time required to achieve temperature and pressure equilibrium within the cell. Moreover, conventional pressure-volume-temperature measurements typically require significant sample volumes, which are typically transported to the laboratory in pressurized containers to preserve the condition of the sample.